Fix wrong argument in autoderef process

Author: ldm0

src/librustc_typeck/check/autoderef.rs

@@ -114,10 +114,10 @@ impl<'a, 'tcx> Autoderef<'a, 'tcx> {
 
         let tcx = self.infcx.tcx;
 
-        // <cur_ty as Deref>
+        // <ty as Deref>
         let trait_ref = TraitRef {
             def_id: tcx.lang_items().deref_trait()?,
-            substs: tcx.mk_substs_trait(self.cur_ty, &[]),
+            substs: tcx.mk_substs_trait(ty, &[]),
         };
 
         let cause = traits::ObligationCause::misc(self.span, self.body_id);